Process of producing a new catalyst



I Patented Dec. 18 :1928.

UNITED STATES.

PATENT OFFICE.

KARL scHIRMAoHEn Nn FRIEDRICH STOLZ, or ocHsT-oN-THE-MArN; Ann-HANSSCHLICHENMAIER AND WALTER KROHS, 0F SODEN-ON-THE-TAUNUS, GERMANY,ASSIGNORS no I. G. FARBENINDUSTRIE AKTIENGESELLSCHAFT, or rnanxrornr-ONTHE-MAIN, GERMANY, A. CORPORATION GERMANY.

rnocnss or Piionucme' A NEW CATALYST.-

. No Drawing. Application filed July 19, 1926, Serial No. 123,591, andin Germany July 22, 1925.

Through a grcatn-umber of pertinent publications it is known thatnickel, particularly in the form of a fine precipitate, when used on asubstratum is well suited for carrying out catalytic reductions ofanykind. But it is also known that certain reductions cannot be effected bymeans of a catalyst consisting merely ofnickel or that they can only becarried out at a very. high. temperature and then only with a very lowyield of hetero-.

gencous final products. For the above stated reasons a number of methodshave been proposed by which it is possibleto obtain considerably betterreductions, namely if instead of the pure nickel mixtures thereof withothermetals are used, for instance with those of'the ironor silvergroups. But also in such cases the operations must generally be carriedout at a. high temperature.

Now we have found that it is possible to effect the said reductions suchas hydrogcnizing processes at a lower temperature and within aconsiderably shorter time, if when 'using for this purpose metalsactingas catalysts such as nickel alone or nickel mixed with a metal of theabove mentioned groups, the precipitation of the metal compounds or themixtures thereof on the carrier is effected not in a fine colloid-likeform but in an ex.- tremcly fine crystalline form."

Ourexperiments have proved that this highly-active form of the catalystis obtained if the preciptation of thenickel compounds on the carriersis carried out in the heat either in the presence of-ammonia with air asa hydroxide or with asoluble carbonate as a carbonate and so slowly thatthe separating bodies have sufiicient time to separate in a crystallineform, whereupon the nickel compound'which precipitates on the carrier istreated with hydrogen at a rather high temperature preferably up to, 550'C. -'The carbonates of the alkalies have proved to be a most suitableprecipitant for the nickel compounds. When using ammonia compounds ofthese metals it is advantageous to eflect the precipitation bycarbonated air. 'Also such nickel compounds 1n a crystalline form may beemployed, which contain a residue which is eliminated by heating withhydrogen.

Furthermore, it is necessary, when. reducing the metal compounds forinstance carbonates with hydrogen, to raise the temperanecessary to worktureto such a highde ee that a complete reduction of the crystallinesalts to the metal:

he nickel is attained. For this purpose it. is i and above. I

The catalysts thus obtained are exceedingly active so that they permitin many cases to reduce 'or-to add hydrogen even at tem- 'number ofuseful compounds, which could only be carried out hitherto by means ofcatalysts prepared from the noble metals, now there can be used a cheapmetal catalyst.

Furthermore the nickel catalyst-prepared in the described mannerhas thevery important property of being resistant against poisoning influences,for instance against halogen or sulfur.

give good 'results even in such cases where they could not be obtainedhitherto; in other cases it is possible to increase considerably theyield. For instance there is obtained from acetone even at 4070 C. in avery short time a yield of about of isopropylalcohol; fromacetonitrile.which according .to Bran-n (see Berich'te (ilerv deutschenchem.

at temperatures up to 450 The catalysts prepared our new process As aproof of the high efficacy of the catalysts thus obtainable may bementioned that when using them hydrogenatingprocessesi can be carriedout which; could-not hitherto be performed when using nickel ascatalyst,

for instance. The reduction of pyridine and piperidine, the reduction ofketo'carboxylic acids to diphenylmethancarboxylic acids, the reductionof ketocarboxylic acid esters 'to ,G-oxybutyric acid esters, thereduction of aliphatic nitriles to primary amines. Furthermorehydrogenatingand reducing processes, which'hitherto hadveryunsatisfactory resalts, are considerably improved, for instance.

the reduction of aromatic nitriles to amines,

of nitro-,nitroso-, a-zoxyand azo comossible heretofore. Owing to itsextremely.

igh eflicacy our new catalyst is particularly useful in cases wheregraduated reductions are to be effected. This is rendered possible bythe fact that the various degrees of temperature as they are requiredfor the reduction of the respective groups, are sufliciently distantfrom each other when using our catalyst. In all the above mentionedcases when using the said catalyst no mixtures, but homogeneoussubstances are obtained. All those reductions can be carried out inpractice in averysim le manner. Theymay be carried out either in absenceof a solvent and when the bodies are in a molten state, for instance inthe case of the reduction otbenzophenone to diphenylmethane ofacetophenoneto ethylbenzene, of naphthonitrile to phenylmeth lamine, ofindone to hydrindone, of anisol to hexanitroanisol; or in the presenceof a solvent, as for instance water, alcohol, aniline, decaline,chlorbenzene etc. Compounds capable of formingv water-soluble salts,such as carboxylic acids, sulfonie acids, nitro-phenols, may be reducedin the form of their salts. Diflicultly soluble com ounds may be reducedin an aqueous or a coholic suspension. The reduction occurs in this casevery easily too. The pressures and temperatures required for thereductions in question, are extremely low. It will be sufiicient on theaverage to use a pressure of 15Qatmos. while the temperature may be inmost cases below 100v G. v

The following examples illustrate our invention, but are not intended tolimit it thereto, all parts being by weight: I

1. 290 parts of nickel nitrate in 3000 parts of water are mixed with 660parts of an ammonia solution of 25% strength and then parts of a finelypowdered silicic acid gel are added.- The mixture is heated to 7 0 C.and a vigorous current of air, free from any particles 5f dust, ispassed through. -The temperature and the volume of the mixture must bekept constant during the passage of the air current. After about 4 hoursthe precipitation of the nickel is complete. The precipitate is filteredoff by suction, washed free from nitrate and dried at about 100. Afterbeing pulverized,the precipitate forms an extremely fine crystallineflour-like substance.

70 parts of the powder so obtained are charged into a wide reductionpipe. The pipe is then heated at first to 100-130 0., while slowlypassing hydrogen through it.. When,

the formed water does no more escape as vapour, the temperature isgraduall raised during 5-6 hours to 415-420 C. his temperature ismaintained until no further formation of water can be detected.Thereupon the pipe is quickly cooled and the catalyst with the hydrogenis still passing over it, is poured into a suitable sus ending agentsuch as water, pyridine, decalme. It forms a doe black substanceconsistin of extreme y fine flakes and depositing very slowly.

2. 290 parts of nickel nitrate are dissolved in 1000 parts of water and50 parts of silicic acid gel are added. The resulting mixture is heatedto 70 C. and 106 parts of sodium carbonate, dissolved in 3000 parts ofwater,

stirring. The precipitate thus formed is further treated and reduced asindicated in Example 1. Y Y

3. 250 parts of nickel nitrate, 70 parts of cobalt nitrate and 10 partsof copper nitrate are dissolved in 2000 parts of water, then mixed with50 parts of absolutely pure silic-, ic acid gel. The resultin mixture isheated to approximately 70 C. here is then added while stirring wellwithin 8.hours the calculated quantity of a. solution of sodiumcarbonate of 3 4% strength, during which 0 eration the temperature is tobe kept at 0. The precipitated carbonates are filtered off by suction,the filtrates are washed free from nitrate, dried at about 100 C. andthe resulting substance, which formsv an extremely fine powder isreduced as indicated in Example 1.

4. parts of propionitrile mixed with one part of thenickel catalyst aresubjected in an autoclave provided wlth a stirrer to a hydrogen pressureof 15 atm. The mass'in the vessel is heated, the pressure rises at firstslowly and at there 15 a lively absorption of hydrogen. The pressure isallowed to go down to' 5 atm. w ereupon each time the pressure is raisedagain'by introducing fresh hydrogen to'15 atm. The temperature at whichthe reduction occurs lies at about In the course of 2 hours the hydrogenabsorption is complete. The content of the bomb, after being cooled, isfiltered ofi by suction, washed with ether and the normal propylamine,which crystallizes well, is precipitated by means of gaseoushydrochloric acid in the form of its hydrochloride. The

analysis shows that the product is a pure pri-.

are added by drops within 8 hours while' mary hydrochloride. The yieldamounts to about 80 of the theory. In the same manner as propionitrilewere reduced acetonitrile, benz lcyanide, paranitrobenzylcyanide anda-nap thonitrile with a yield of respectively 63% of primary and 18% ofsecondary base, 50% of primary base, 70% of primary base and 20% ofsecondary base.

5. 500 parts of pyridine are hydrogenated in the presence of 30 parts ofthe catalyst in an autoclave at a temperature-of 130-180 and at apressure of- 20-40 atm. After 3 hours, the absorption of hydrogen iscomplete. The catalyst 'is isolated from the mass by decantation anrhthepiperidine is fractionated.

Like piperidine also quinaldiuc, Q-methyl- 5-ethylpyridine, anda-a-lutidine-fi-carboizy lie acid methylester and dihydrolutidine lcarboxylic acid ester were completely hydrogenated. u

6. 105 arts of aceto acetic ester and I parts of t e nickel catalyst aresubjected in I an autoclave provided with a stirrer to .a

:ihydrogen pressure of 20 atm. and .slowly heated. The absorption ofhydrogen sets in at 90, the temperature is then raised to 110..

The pressure is allowed to go down to atm.

and is'then raised each time to atm. by introducing fresh hydrogen,until no fur-. ther absorption of hydrogentakes place.

The reduction is complete in about minutes. .After cooling, the catalystis filtered off by suction and distilled. Thus there is obtained besidessome B-oxytutyric acid pure ,Bpxybutyric acid ester in a very goodyield. .7. 244 parts ofp-toluylbenzoic acid are dis- I-solved in '53parts ofsodium carbonate and amounts'to about 95%.

:26. 1000 parts of Water. This solution is mixed with 7 parts. of thenickel catalyst. and subjected in an ironfpressure bomb provided with astirrer to a hydrogen pressure of 20 atm. The mass is heated whereuponthe hydrogen absorption sets in at46 C. whilst the pressure begins tofall. The temperature is then raised to 110 C. and the pressure'isallowed to go down to 10 atm'. and then again raised each ftimeto QOatm. by introducing fresh hydrogen. After about 4 hours the hydrogenabsorption ceases. The nickel catalyst is thenfiltered off by suctionand from the clear filtrate-the toluylphnylme'than carboxylicacid'iszobtained by acidification.

This acid is almost pure and can be obtained in an absolutely pure stateby a single recrystallization from alcohol. [The yield 8. 26,4 2' parts(1/10' molecule) toluylbenzoic acidof the formula are dissolved in 5,3parts of sodium carbonate and-200 parts of water andtreated in the ofo-nitro manner indicated in Example 4 with hydrogen in the presence ofone part of the nickelcatalyst.

The reduction of the nitro group begins already at 30 C. "The pressuregoes down and remains constant when the hydrogen required forthereduction of the nitro group to the amino'group has been absorbed.

The reduction of the ketogroup to 'the methane-group requires a' highertemperature.

The mass is heated to 110 and the pressure is.

again raiscdto" 20 atm. The hydrogen is quickly absorbed and thepressure, after the calculatedquantity of hydrogen is consumed v (2/10molecule) remains constant. After.

cooling the catalyst'is filtered off by suction and by means of acetic.acid the diamino- 'methyldiphenylmethan-o-carboxylic acid isprccipitatedas a mass which is at first soft but-soon solidifies intocrystals. Recrystallized from benzene, the acidinelts at 135- 136. It isdifliculty soluble in water, more readily soluble in benzene and; veryreadily soluble in alcohol, the yield amounts to over %017' the theory.

In an analogous manner -there isre-. duced 4,4-dimethoxy-22dinitrodiphenlyketone to 4.4-dimethoxy-22Qdiaminodiphenyb' methane in aquantitative yield; 4 -methyl-3 -nitrodiphenylketone to4-methyl-2-aminodiphenylmethane in a very good yield, 4.4-dimethyl-3-nitrodiphenylketone to 4.4-di- .methyl-3' diphenylmethan-e,benzophenone to diphenylmethane and acetophenone to cthyl-v constant. HY 9. 500 parts of p-nitraniline, suspended in 1500 parts of Water, aremixed with 5 parts of nickel and treated with hydrogen in the mannetabove described. The absorption of the hydrogen sets in at 40 andproceeds so energetically, that the heating must be discontinued at 60C. If an average pressure of 10'15 atm. and a temperature of 7080 ismaintained, the reaction is finished in hour. The product being workedup an almost quantitative yield of pure .paraphenylene'diamine isobtained-.-

10'. 33,4 parts of p-nitrobenzoic acid, dissolved in 10,6 parts ofsodium carbonate and parts of water, are mixed. with 0,5 parts of thenickel catalyst and treated in the above described manner with hydrogen.The absorption of the hydrogen begins at room temperature and iscompleted in a short time. The product after being worked up is obtainedwith an almost quantitative yield of entirely pure p-aminobenzoic acid.

In an analogous manner the following compounds can be reduced in a'veryshort time and at temperatures below 100 to the corresponding amineswith a very good yield a-nitronaphtha'lene, meta-dinitrobenzene, o-

nitrophenol, 2'-nitro-4-cresol, o-nitrochlorobenzene, 1.4chlornitronaphthalene, potassium o-nitrobenzenesulfonate, o-nitroaoetan-.ilide, 2-nitro-l-oxyr4-benzoic acid ester, 1.5-

= reduction a finely crystalline nic nitronaphthoic acid and1.8-nitronaphthoic acid, p-nitroacetanilide, nitro-2.5-dichlorobenzene,benzeneazosalicylic acid, azoxybenzene, 5-nitroacenaphthene,m-nitr0-m.'-car.- bomethoxy-p-oxybenzophenone, o-nitro-pcresolcarbonate,4-chloro-2-nitrophenol.

11. 5000 parts of crotonic aldehyde, mixed with parts of the nickelcatal st, are subjected in a stirring-drum to a hy rogen pressure ofabout 20 atm. pressure. The pres- "sure begins to diminish even at roomtemperature. The temperature rises quickly and the absorption of thehydrogen proceeds energetically so that there must be taken care for asufficient cooling. Thus-the temperature is maintained at 50 while thepressure is allowed to go down each time from 25 to 15 atm. Towards theend of the operationthe temperature is raised to 5060 C. The absorptionof the hydrogen is complete 'in about 4 hours.

The catalysts of the present invention may be characterized as looseblack powders, which form water when treated with hydrogen and oxygen.at ordinary temperatures, reduce acetonitrile to ethylamine at atemperature of about 70 to 80 0., and, in the dry state, spontaneouslyignite when brought into contact with the air.

In .the following claims the term substratum is to be understood as aninert, non-reducible material such as, for instance, kieselguhr,asbestos, or pumice stone.

. Claims: 1 i

1. A process of making a; highly active nickel catalyst which comprisessubjecting to el' compound associated with an inert substratum.

2. A process of making a highly active nickel catalyst which comprisessubjecting to reduction a finely crystalline nickel compound of theformula N1.=X, whereinX represents (OH) 2 or C0,, associated with aninert substratum.

3. A process of making a highly active 1 nickel catalyst which comprisessubjecting to reduction a finely crystalline nickel carbonate compoundassociated with an inert sub- I stratum. v

4. A process of making ahighly active nickel catalyst which comprisessub]ecting a finely crystalline nickel compound of theformula Ni=X,.wherein X represents '(OH) 2 or C0,, associated with an inertsubstratum,to reduction with hydro en.

5. A process of making a big ly active nickel catalyst which comprisessub ecting a finely crystalline nickel compound of the formula Ni=X,wherein X represents (OH) 2 or C0,, associated with an inert substratum,toreduction with hydrogen, at a temperature between 400 and 600 nickelcatalyst which comprises subjecting a finely crystalline nickelcarbonate compound, associated with an inerts'ubstratum, 1

to reduction with hydrogen at a temperature of bet-ween400 and 600 C.

7. A process of making a highly active nickel catalyst which comprisesprecipitating a nickel compound of the formula Ni=X, wherein Xrepresents (OH) 2 or C0,, in finely crystalline form, in the presence ofan inert substratum, and thereupon subjecting said compound to reductionwith hydrogen at a temperature of between 400 and 600 C.

8. A process of making a highly'active nickel catalyst which comprisesprecipitating in finely crystalline form a nickel carbonate compoundfrom a dilute solutionof a nickel compound, in the presence of an inertsub-' stratum, and thereupon subjecting said nickel carbonate compoundto reduction with hydrogen at 400 to-600 C.

9. A process of making a highly active nickel catalyst which comprisespreclpitating in finely crystalline form a nickel carbonate compound.from a solution containing rom 0.5% to 1.5% of nickel, in the presenceof an inert substratum, and thereupon subjecting said nickel carbonatecompound to reduction with hydrogen at 400 to 600 C.

'10. A process of'making a highly active nickel catalyst which comprisesprecipitating V in finely crystalline form a nickel carbonate compoundfrom a solution containing from 0.5% to 1.5% nickel at a temper' turebetween 70 and 80 C., in the presence 0 an inert substratum, andthereupon subjecting said nickelcarbonate compound to reduction withhydrogen at 400 to 600 C.

" 11. As a new roduct, a highly active nickel catalyst o tainable bysubjecting a finely crystalline nickel compound of the formula N1==X,whereinX represents (OH) or C0,, associated with an inert substratum toreduction with hydro en at a temperature between 400 and 600 12. As anew product, a nickel-catalyst comprising active nickel materialassociated with an inert substratum, which catalyst is a loose blackpowder, and which forms water when treated with hydrogen-and oxygen atordinary temperatures, reduces facetonitrile to ethylamine at atemperature ofabout 70 to 80, and, in the dry state spontaneouslyignites when brought into contact with the air.

I In testimony whereof, we aifix our signatures. i

' KARL SCHIRMAGHER.

- FRIEDRICH STOLZ. HANS SCHLICHENMAIER: WALTER KBOHS

